In the recent Constitutional Court Judgement between Allan Long and SAB (CCT 61/18), the highest court in the land held that where an employee is suspended as a precautionary measure in order to prevent interference with a pending investigation, there is no requirement that the employee be given an opportunity to make representations to the employer.
The Constitutional Court held that:
Where the suspension is precautionary and not punitive, there is no requirement to afford the employee an opportunity to make representations.Allan Long v South African Breweries (PTY) LTD CCT61/18 (ConCourt) at Para 
As well as that:
In determining whether the precautionary suspension was permissible, the Labour Court reasoned that the fairness of the suspension is determined by assessing first, whether there is a fair reason for suspension and secondly, whether it prejudices the employee. The finding that the suspension was for a fair reason, namely for an investigation to take place, cannot be faulted. Generally where the suspension is on full pay, cognisable prejudice will be ameliorated. The Labour Court’s finding that the suspension was precautionary and did not materially prejudice the applicant, even if there was no opportunity for pre-suspension representations, is sound.
Allan Long v South African Breweries (PTY) LTD CCT61/18 (ConCourt) at Para 
This means that the previous Judgements which related to the fairness of suspension and required that the employee be afforded an opportunity to make submissions as to why he/she should not be suspended no longer apply to precautionary suspensions.
A precautionary suspension is, in terms of this judgement, such suspensions wherein an employee is suspended on full pay for the purposes of finalizing an investigation or, in some cases, to prevent an opportunity for an employee to cause further damage to the employer.
Where you are uncertain as to whether or not a proposed suspension would be protected, it is recommended that you seek professional advice before implementing such a suspension.
The Full Judgement is available for download Here.